This invention relates generally to the dispensing of food sauces and other foods and more particularly to an improved end construction for sauce dispensing cartridges.
Fast service restaurants and other food service facilities use various types of food sauces that are applied to sandwiches and other foods. Due to the large volume of customers that are served by fast service restaurant chains, the sauces must be dispensed repeatedly in carefully controlled portions each containing a relatively small amount of sauce. Particularly in applications of this type, it has proven to be convenient for the sauces to be packaged in cartridge dispensers from which the sauce is dispensed using handheld dispensing guns. The amount of sauce that is dispensed is controlled by providing suitable valving in the dispensing end of the cartridge and using a dispensing gun that advances a plug in the cartridge a consistent distance each time the dispensing gun trigger is squeezed.
Examples of the type of dispensing cartridges that have been used include U.S. Pat. No. 4,432,473 to MacEwen and U.S. Pat. No. 4,830,231 to Smith. Although cartridges of this type have functioned well for the most part, there is room for improvement, particularly with respect to the construction of the bottom disk and its connection with the body of the cartridge.
It has been common practice in the past to use xe2x80x9chot meltxe2x80x9d adhesive to glue the end disk to the inside of the cartridge wall. Such adhesives are typically applied to the inside surface of the disk and cartridge wall where they are in contact with the food sauce contained by the cartridge. Accordingly, the adhesive must meet food grade standards. Such adhesives are relatively expensive and also complicate the manufacturing process due to the need for the adhesive to be heated and accurately applied. The adhesive must be applied in a bead or fillet completely around the periphery of the disk in order to prevent leakage of sauce past the edge of the disk. Also, the raw edge of the disk must be isolated from the sauce by the adhesive in order to prevent the sauce from xe2x80x9cwickingxe2x80x9d into the paperboard edge of the disk. Many adhesives do not exhibit good temperature or chemical resistance properties, which limits the types of products that can be packaged in the cartridge. The end disk constructions that have been used in the past in dispensing cartridges normally recess the disk a significant distance inwardly from the end of the cartridge body. Because the food sauce can be filled only to the end disk, the volume of the cartridge body located beyond the disk is unavailable to hold the sauce. When pressure is applied to the end disk during dispensing of the sauce, the disk can bow or otherwise deform because of the relatively weak construction of the disk itself and particularly its connection with the cartridge body. This flexure can create problems in the dispensing of the sauce.
The present invention is directed to a food sauce dispensing cartridge that has an improved end disk construction. More specifically, the invention is characterized by an end disk that is initially positioned inside the dispensing end of the cartridge body with a peripheral skirt lying along the inside of the cartridge body wall and the end portion of the cartridge wall extending beyond the skirt. The wall end portion is crimped or folded inwardly to lie along the outwardly facing surface of the end disk. This folds the skirt into the form of a lip which is doubled over onto the peripheral portion of the disk. Heat is applied during the crimping process to melt the thermplastic which coats the surfaces of the disk and cartridge wall. When the thermoplastic cools, it forms an effective heat seal between the disk and the cartridge body.
The folded or crimped end portion of the cartridge wall provides an in turned flange which is heat sealed to the lip on the disk and to the main disk surface. The disk sandwiches the lip and its raw edge between the main disk surface and the flange so that the raw paperboard edge of the disk is enclosed. This isolates the disk edge from the product contained within the cartridge body. Further, a strong connection is provided because the fold on the periphery of the disk is heat sealed to the cartridge wall and the flange on the cartridge body is heat sealed to the lip and to the main surface of the disk. The folded over lip provides an extra layer of paperboard at the connection area, and the flange provides still another layer of material that strengthens the connection and reduces the tendency for the end disk to bow or otherwise deflect when the sauce is being dispensed.
This construction eliminates the need for costly xe2x80x9chot meltxe2x80x9d adhesive and also provides better temperature and chemical resistance than cartridges that use such adhesives. The cartridge has a substantially flat end configuration so that the disk is adjacent to the end of the cartridge body, thus making the entire length of the cartridge available to hold the food sauce. Wicking of the food sauce into the raw edge of the disk cannot occur because the disk edge is completely enclosed by the folded flange. The overall result is that the dispensing cartridge is economical to make, exhibits good temperature and chemical resistance, has enhanced strength, and provides more volume than cartridges with recessed end disks.